1. Field of the Invention
Exemplary Embodiments of the present invention relate to a thin film transistor array panel and a manufacturing method thereof.
2. Discussion of the Background
Generally, a thin film transistor (TFT) array panel is used as a circuit board for independently driving pixels in a liquid crystal display or an organic electro-luminescent (EL) display device. The thin film transistor array panel includes a scanning signal line or a gate line transmitting a scanning signal, an image signal line or a data line transmitting an image signal, a thin film transistor connected to the gate line and the data line, and a pixel electrode connected to the thin film transistor.
The thin film transistor includes a gate electrode that is a portion of the gate wire, a semiconductor layer forming a channel, a source electrode that is a portion of the data wire, and a drain electrode. The thin film transistor is a switching element controlling an image signal transmitted to the pixel electrode through the data wire according to the scanning signal transmitted through the gate line.
To reduce the number of processes using a mask when forming the thin film transistor array panel, the data line and the semiconductor layer may be formed by using one mask. That is, the side wall of the data line and the side wall of the semiconductor layer accord with each other. However, when etching the metal of the data line layer, the side wall of the data line and the side wall of the semiconductor layer do not accord with each other due to the increase of a skew, which may result in protrusion of the semiconductor layer from the data line.
As a four-mask structure is introduced in a process to simplify TFT-LCD panel production and reduce cost, screen display deterioration (i.e., a waterfall) may chronically occur. The waterfall problem occurs because the semiconductor layer exposed outside the data wire acts as a conductor when a backlight is turned on such that the semiconductor layer forms a capacitive structure with the pixel electrode, thereby creating vertical lines that continuously flow from the top to the bottom of the display under modulation of the backlight.
The above information disclosed in this section is to enhance understanding of the background of the invention, and it may contain information not part of the prior art already known in this country to a person of ordinary skill in the art.